The objective of this program is to induce oat cell carcinoma of the lung in rodents and to thoroughly characterize the tumors. Methods of analysis include white light microscopy, electron microscopy, cytology, histochemistry and biochemical analysis. In addition, tumor transplantation and tissue culture isolation will be used to perpetuate a tumor line of pulmonary oat cell carcinoma. Preliminary experiments by the author have resulted in the induction of an "oat cell like" lung carcinoma in rats. The rationale for this study is to exploit the methods of the preliminary experiments to induce and characterize pulmonary oat cell carcinoma. Male and female Sprague-Dawley (laboratory-bred) rats were exposed to mixtures of dimethylbenzanthracene with charcoal and benzo-a-pyrene and ferric oxide. After exposure, Type II cell proliferation was observed followed by squamous metaplasia. Squamous cell microtumors were in evidence six weeks after exposure to the carcinogens. Oat cell like neoplasms have not been observed as yet (6 months) and are not anticipated for several more months.